The Mystery of «the rotators»

par Eric FLORIN and the parisian group of A.P.E.

     Constantinesco and Autet, first (1984), then Villeneuve and Parpay (1991) put forward observing variations of the postural tone, under various manipulations, by testing the tonus of hips external rotator muscles on the patient in decubitus position. Techniques of these authors are different, they have been named differently: "The rotators test" and "The feet convergence maneuver" but, till now, they share the same lack of validation.
     This absence of validation did not prevent the spreading (Gagey et al., 1994; Gagey & Weber, 1999) and generalized utilization of these tests, they are so quickly and easily handled! More, they do not represent, far from it, a sure criterion for therapeutic decision. They are used as maneuvers "to see" that feed the subconscious work of the therapist spirit, like many other observations gathered in the course of clinical examination, that's all.
     One could qualify flightiness, thoughtlessness, this massive usage of a non-validated test. But this criticism does not touch us because we know now that this risky experience of posturologists today allows us to assert a contradiction and we can assert it all the more strongly as this experience has been more largely spread and shared. We know that till now we do not know if these tests are repeatable and nevertheless we are quite sure that they allow us to test a change of the muscle tone! Such is our assertion that deserves being criticized, at least.
     All began with Eric Florin. He wanted, for his student thesis, to test this hypothesis:«Rotation of the head of a subject in decubitus position brings about a modification of the hip external rotator muscles tone that can be explored by evaluating the resistance to stretching of these muscles». In December 1999 Florin therefore organized an experience according to the following protocol. Six clinicians tested successively the rotator tone of 15 subjects in three positions of the head (Head in neutral position, rightwards rotated, and leftwards rotated). After having taken enough time to become accustomed to tonic replies of each subject, clinicians were blindfolded and had to tell in what position was the head of the subject; the head was rotated or not according to random orders. To tell whether the head of the subject was rotated and what side it was turned, clinicians therefore had no other information than the rotator muscles tone. Results of the statistical analysis of this experimentation were quite clear: no clinician was able to tell the position of the subject's head. And Florin concluded: «In the conditions used by our study, we cannot confirm the hypothesis of the manually perceptible influence of the neck reflex on the hips external rotators muscles tone.»
     On the 23rd of March 2000, the Parisian group of the 'Association Posture et Équilibre' (APE), knowing the current results of Florin, organized, with him, a working evening on the validation of these tests. As the first hypothesis to explain the "failure" of Florin's experience consisted to query the training of the six clinicians for the delicate practice of these tests, all the "Fathers", and other leaders of these methods, concerned by the question, came to the 'Institut de Posturologie' for a memorable evening. Neither Patrick Guillaume, nor Sylvie Villeneuve-Parpay, neither Alain Scheibel, nor Pierre-Marie Gagey found better than Eric Florin and his clinician colleagues, if and how the subject's head was rotated! None of us succeeded giving the position of the head based on the reply of "the rotators test" or of "The feet convergence maneuver". Worse, knowing our first failure, we simplified the protocol, instead of two head positions we retained only the one that brought about the strongest variation of the tone according to the 'feeling' of the clinician, nevertheless the results were not more brilliant.
     This failure strongly heckled participants. Some of them, as Eric Blin, saw in this failure a good reason to seek another test to replace these rotators tests that suddenly appeared so random, others preferred to seek the reasons for this check. Bonnier put forward the hypothesis that the test was no longer the same when a screen was put between clinician and patient. Scheibel thinks that tonic asymmetries are more marked among patients than among normal subjects and that could explain uncertainties of clinicians. Weber estimates that, in any case, it is necessary to work on all contradictions because very often they teach us quite a lot.
     On the 27th April 2000 the Parisian group of APE gathered again to discuss on the same subject of the validation of rotators tests. First we began testing hypotheses by suppressing the screen between clinician and subject; the modification of the muscle tone was no longer induced by a rotation of the head but by putting an asymmetrical bite plane, then by stimulating the feet sole. During the stimulation time, the clinician turned and when he returned for the test, at this time he could see the whole body of the subject. According to the variations of the muscle tone, clinicians had only to tell stimulation did or didn't take place when he was turned. Only one examiner gave replies that were not strictly random, they were all and systematically false!
     After these two evenings therefore, the question remains untouched and more teasing than ever: How can we claim that we are able to test a variation of the tone with a maneuver that, apparently, we are unable to test if it is repeatable or not?
     Nevertheless posturologists would rather choose a postural stimulation by using one of these tests than by mere chance, and tens of them or so have been doing thus since more than ten years. They observe certain coherence between these tests and other postural clinical tests (Fukuda's stepping test, Thumb's test, Barré's test, and Posturodynamic test), and with therapeutic results and/or stabilometric parameters. This long practice of the rotator tests does not give them the feeling of a random maneuver but rather the certainty of the contrary. Nothing is more harmful, indeed, than false certainties; I do know something on this matter: the only day I smashed the door of my garage, I had the certainty that my foot was on the brake pedal of my car! But one does not throw his certainties to the trash without looking into them once again.
     In the course of postural clinical examination of a patient, when clinician uses one of the rotators tests, he seeks to perceive not an indication of position or an indication of state, but an indication that the transition from a state A to a state B brings about a postural tonic modification. When we want to seek if these tests are repeatable as clinicians use them, it does not suffice to insure that the presented state B' is exactly similar to the state B that clinician is supposed being able to recognize, it is necessary to insure also that the state B' similar to B is presented after having presented a state A' similar to the state A. And logically it is necessary to be sure that the transition from A' to B' is similar to the transition from A to B. A simple example can be given from the daily practice: if the B position of a prism, say OG55, entails the fall of the right rotators tone, it would be necessary to note the previous position A of the prism, say OG180, in order to be able to verify that the transition from A', OG180, to B', OG55, again brings about a fall of the right rotators tone if the transition is made as quickly, and in the same environment, the same vigilance, the same etc. "One never bathes twice in the same river, indeed" said Parmenid quite a long time ago!
     Knowing the fluidity of the postural tone, largely described by authors as remarkable as André Thomas and Juan de Ajuriaguerra (1949), one can question usefulness of a stubborn research for the protocol that would allow proving the rotators tests are repeatable. Why not simply to tell: We know that we do not know if these tests are repeatable but we have the obviousness that they allow us to test a change of the tone and the development of this obviousness through consciences of posturologists is a truth criterion as good as the one that would be provided by a successful, but always criticizable, protocol. In any case objectivity is always the term of intersubjectivity.


AUTET B.M. - Examen ostéopathique prenant en compte l'activité tonique posturale. Mémoire de la Sereto, Montpellier, 1985.

GAGEY P.M., BIZZO G., BONNIER L., GENTAZ R., GUILLAUME P., MARUCCHI C., VILLENEUVE P. - Huit leçons de posturologie. Editées par l'Association Française de Posturologie, 4, avenue de Corbéra, 75012 Paris, Quatrième édition, 1994.

GAGEY P.M., WEBER B. - Posturologie; Régulation et dérèglements de la station debout. Deuxième édition. Masson, Paris, 1999.

MATHURIN B. Le test des rotateurs : recherche de l'asymétrie tonique segmentaire. In M. Lacour et B.Weber (Eds) Posture et équilibre, Bipédie, contrôle postural et représentation corticale, Solal, Marseille, 2005, 289-293.

THOMAS A., de AJURIAGUERRA J. - Étude sémiologique du tonus musculaire. Flammarion, Paris, 1949.

VILLENEUVE Ph., PARPAY S. - Examen clinique postural. Rev. Podologie, 59, 37-43, 1991.

The point of view of the philosopher
          I have naturally no relevant idea on the matter of the history: what interest would you have validating the test in question? Will it be possible to succeed, though the first attempts made in this direction have failed?-
          I approve on the other hand the philosophic position which you try hard to take with regard to what could be supposed to be for a pure stubbornness of posturologues. A really enlightening theory  of what is the experimental check is lacking to us and to say significant things on the subject requires certainly at least that one makes a place to the clinical sensibility of the experimenters. It is always present and active even if they offend its impact when they believe to have met the pure objectivity. It is never without interest when they have nothing else to share than only a certain convergence of their expectations.